In 2020, the developers announced a major change to Minecraft: Java Edition, as players would soon have to switch from the Mojang account to an Microsoft account to continue playing. Although it's still an incredibly long time to wait, the developers have confirmed the date and released the final call for account migration.
You'll no longer have the ability to play Minecraft: Java Edition if you have an account with Mojang account. The devs want everyone to switch to Microsoft accounts for "improved security and player safety" and are entice people to make the change by offering free Minecraft capes.
Here are all the information about how you can migrate your account. MINECRAFT SERVERS will continue to be supported in the normal way after the change and will continue to be a distinct entity from Bedrock. This is simply a reunification of the account system. You can use your old username. All you need is an Xbox gamertag.